Earth ‘in the crosshairs’ of a solar explosion

A powerful solar flare, hurled into space when superhot gases erupted on the sun Sunday, might cause a display of the aurora borealis for parts of the northern United States overnight Monday night.

The sun unleashed the solar flare yesterday at about 12:30 p.m. EST from a sunspot region that was barely visible last week. Since then, it has grown in size to more than 62,000 miles across — nearly eight times the width of our Earth.

The flare was categorized by the NOAA Space Weather Prediction Center in Colorado as a Class M6.6 and is the strongest solar flare observed in 2011. It could ramp up northern lights displays for skywatchers living in northern latitudes and graced with clear skies.

Such a flare, covering more than 1 billion square miles of the sun’s surface (called the photosphere), was described as “moderate” in intensity. Class M flares are stronger than the weakest category (Class C). They are second only to the most intense Class X solar flares, which can cause disruptions to satellites and communications systems and pose a hazard to astronauts in space.
NOAA’s Prediction Center has forecast the possibility of additional solar flares from the same sunspot region over the next two or three days.